Strong, lightweight, and highly conductive CNT/Au/Cu wires from sputtering and electroplating methods

Abstract In this study, we present a 2-step deposition method via sputtering and electroplating that uses carbon nanotube (CNT) wires synthesized from a wet-spinning technique to produce high-performance CNT/Au/Cu composite wires. After the Au sputtering pre-treatment, the deposition of Cu on the CNT wires was found to be much more homogeneous due to improved wettability and reactivity of the wire surface. At different electrodeposition time, the mechanical strength of the CNT/Au/Cu composite wires could be as high as 0.74 GPa (∼ 2 times stronger than metal wires) while their electrical conductivity could reach 4.65 × 105 S/cm (∼ 80% of that for copper). More importantly, the CNT/Au/Cu composite wires with high CNT volume fraction are expected to be lightweight (up to 42% lower than Cu mass density), suggesting that our high-performance composite wires are a promising candidate to substitute conventional heavy metal wires in the future applications.